Reframing Attribution

It the previous entry I wrote about the perils and pitfalls of event attribution. In this entry I want to untangle a few issues and, then, ultimately reframe attribution. Reframe? This is in the spirit of psychology and sociology, a different way to look at something. In this case, take the word, “attribution” and think about the meaning of this word, say, from the point of view of scientists, journalists, politicians ….

To be concrete, start with this scenario.

1) There is an extreme weather event, perhaps a hurricane submerges New Orleans, or a heat wave kills 1000s in Moscow.2) Advocates say that the event is global warming.3) Politicians say that the event is global warming.4) Scientists suggest that the circumstances of the event are consistent with global warming.5) Journalists ask if the extreme event is natural or global warming.6) Different groups of scientists hurry to investigate the event. It takes a while.7) The scientists publish their papers and because the event was newsworthy, the journalists follow up and ask again: Was the event natural or was it global warming?

There is in this scenario entanglement. We have scientists, journalists, and politicians. I have explicitly used the plural form to suggest that there are many perspectives, many points of view, many purposes represented. Because of the presence of political interests, the question is being asked in a social environment that is more political than it is scientific.

In the previous entry, I wrote, “It is hard to see how playing the game of defining extreme events and then attributing that event to ‘climate change’ can ever be won. In fact, it seems like it is a game that necessarily leads to controversy, and controversy is the fuel of talk radio, blogs propagating around the world, and the maintenance of doubt.” The game to which I refer is described above: event, fast public attribution of the event to climate change, scientific investigation and deliberation, scientific conclusion that the event is not wholly-and-solely due to climate change. In the formal and informal media, this game devolves to:

“This event is the proof of global warming,” followed some months later by, “No it is not.”

You can read the previous entry on why I maintain trying to attribute a single event to climate change with a yes-or-no answer or to split our weather into natural-and-changed is not scientifically sensible. That does not mean, however, that we should not study extreme events and place them into context with history, a warming climate, and how they inform our future. In fact, I have maintained that one of the most important tasks for climate scientists to take on is the quantification of variability that is “short-term” compared with the “long-term” normally associated with climate. (See Some Jobs for Modelers, and Ocean, Atmosphere, Ice and Land) Which brings me to “attribution.”

“Detection and Attribution: Climate varies continually on all time scales. Detection of climate change is the process of demonstrating that climate has changed in some defined statistical sense, without providing a reason for that change. Attribution of causes of climate change is the process of establishing the most likely causes for the detected change with some defined level of confidence.”

In fact, neither of these definitions require a yes-or-no, wholly-and-solely answer that a particular event was “caused” by the warming of the planet by increasing greenhouse gases. That requirement has risen from the quagmire of the public discourse.

In the piece Some Jobs for Modelers I talk about “forecast busts.” These are well known to weather buffs, when weather forecasts fail. It is worst when severe weather shows up unexpectedly. In December of 1999 there was a series of Atlantic storms that hit France which were badly forecast. Detailed examination of the observations, the forecast model, and the ability of model to utilize those observations, revealed that there was adequate information to provide a better forecast. Specific failures in the forecast system were identified. (A complicated paper on those storms: Dee et al. 2001) When I think of attribution and a single extreme event, then I think of the detailed scientific investigation of the processes that come together at the occurrence of that event.

There are many reasons to pose such a study. A basic reason is to understand the physical processes. For example, in a historic heat wave, what is the impact of regional changes in the forest, agriculture, and the urban environment? What are the specifics of the atmospheric flow that allow the development of a period of persistent heat? A perfectly legitimate question is whether or not changes in our environment related to greenhouse gases have had a discernible influence on the event.

So that becomes the question. In the complex mix of processes that are responsible for determining the temperature and winds and rain of an extreme event, is there a discernible contribution that can accounted against, attributed to, climate change? To make it more challenging, climate change is not a simple, unrelenting, uniform warming of the surface. Therefore, if there is to be a discernible signal, then it has to rise above the variability, the noise, that is implied by the complexity described in the previous paragraphs. It is not a question of whether or not an extreme event is caused by climate change, it is what influence might be attributed to the increase of greenhouse gases.

That said, there are many reasons to investigate which processes, which causes, are responsible for an extreme event. A fundamental one is to improve the ability to predict the event. Another reason is to understand the impact of the event, assess the risk associated with such events in the future, and, if warranted, develop the ways to better prepare for such events.

I want to return to the my previous blog, which was motivated by a story that originated in the Green Blog by John Rudolf on the New York Times website (March 9, 2011) about the Russian heat wave in the summer of 2010. The news story reported on a paper by Randy Dole and co-authors. Within hours the Dole et al. paper was headlined on both news sites and in blogs that the paper said that the 2010 Russian heat wave had no relation to global warming. It is a source of continuing and intensifying controversy. ( from Climate Progress, recall that above, I deliberately used the plural of scientist.)

Here is the link to the abstract of Dole et al., Was There a Basis for Anticipating the 2010 Russian Heat Wave? Dole et al. take an approach to the problem that is process-based, in the spirit of the process-based approach to a busted forecast. They search for the signal over the noise, and for the 2010 event cannot state definitively that the signal related to the increase of greenhouse gases exceeds the noise. I want to quote, however, two sentences from the “Concluding Remarks” of Dole et al.

“The results suggest that we may be on the cusp of a period in which the probability of such events increases rapidly, due primarily to the influence of projected increases in greenhouse gas concentrations.”

And looking forward.

“However, as is the case of the 2010 Russian heat waves, events will also occur that are not readily anticipated from knowledge of either prior climate trends or specific climate forcings, and for which advance warning may thus be limited.”

The Dole et al. paper does not state in any way that global warming is unreal. Quite the contrary, they work in a rigorous physics-based approach and investigate this region, at this time, for this event, and ask in the context of a forecasting problem, can a discernible contribution be attributed to human-caused greenhouse gas emissions? Their method, their analysis, their conclusions - that for some highly particular reasons - the climate change signal has not popped out of the natural variability. But as they say, it has in other places, for other phenomena.

Dole et al. provide one scientific approach to the problem of event attribution. There are other approaches. (see Barriopedro et al. The Hot Summer of 2010: Redrawing the Temperature Map of Europe) The conclusions from these results are likely to be different, and that difference may appear inconsequential to some and enormous to others. And while these differences might appear as important to scientists, my point is that this process of event attribution is a place where the scientific investigation of the climate interfaces, strongly,with the media. Therefore, it is also a place where, by definition, scientific investigation interfaces with the political argument. Politically or in terms of informing the public, a primary result of this process is to build, amplify and maintain doubt. Here, I have tried to reframe attribution. Next, on reframing the dialogue.

r

Previous blogs on the disruptions and communications of climate science. (or how can climate scientists contribute to political discrediting of science.)

This graph will show one of the problems I have with the interpretation of temperature proxies. I'll ignore problems with the proxies themselves for the moment. I'll submit that this graph here doesn't show that recent temperatures are unprecedented at all. In fact, let's say I interpret the graph as showing temperatures at the far right (around year 1990-95 or so) as being an anomaly of about -0.15°C--the lowest point of the grey area representing the 2s margin of error. Let's say that I interpret the temperature anomaly of ca.1260 as being about +0.15°C--the highest point of the grey area. This interpretation would give the result that temperatures at the end of the graph were -0.3°C lower than those of 1260.

Is this an invalid interpretation? No, it isn't since it is within the margin of error. As an aside, this margin of error is only what arises from the uncertainty in comparing proxy estimates with the temperature record over the available time period in which they overlap; the true margin of error that would take into account errors in measuring the proxies, global distribution of the proxies, uncertainties in the correlation of the proxies to temperature etc. are likely not included here: the caption accompanying the graph only states that the margin of error shown is due to correlation with the validation period.

Anyhow ignoring that for now in the spirit of brevity, even within the margin of error shown on the graph, the interpretation that temperatures at the end of graph are unprecedented is inconclusive at best, since the opposite interpretation is also within the margin of error.

Another quick point...a lot of people would like to append the surface temperature record to the end of the proxy average in the graph and show that as evidence of how high temperatures are in relation to past points. This is misleading as well. To be within the margin of error, the surface temperature line could just as easily be appended somewhere at the lowest point of the grey area just as easily as one of the highest points of the grey area and not be any more right or wrong. In fact, the temperature data could be applied at anywhere within the overlapping margins of error of both the temperature data as well the proxy data and still be valid. Additionally, since a 39-year filter was used to make the proxy graph, a temperature graph would need to be smoothed similarly to maintain context. Every graph I have seen that has temperature readings appended to a temperature proxy graph seems to ignore these points entirely.

Of course, I could probably write several more paragraphs about the precision of the proxies themselves but I'm going to leave that for now...

As always, the opinion above is my opinion, and goes to try to present my point of view of why I am unconvinced of statements such the initial one I quoted.

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№ 281@TomTaylor

I'm going to refrain from quoting it here, as this is already going to be a long post. You bring up a lot of good points here. I definitely agree that it is very difficult to say that human haven't contributed to warming at all; it is simply to easy to list ways in which we have. The UHI (Urban Heat Island) effect is one that I find interesting. I suspect that there is a significant UHI signal in the surface temperature myself, even though they try to adjust for it using an automated algorithm based on night-time illumination. Many studies that I have seen seem to suggest that the UHI is relatively small, even if it weren't compensated for; but I can't say that I am convinced. Of course, it's overall contribution to actual warming, and not just the warming measurements, is interesting as well.

I do agree that even if one doubts the accuracy of the surface temperature record, there are many other empirical ways to verify general warming over the last 100 years or so, as well as a significant period of warming in the ca.1975-2000 period as well.

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Concerning but not replying to № 283:

I guess what MichaelSTL means when he says that the Aqua temperatures have a "cold bias" compared to UAH temperatures is that Aqua temperatures are consistently colder than UAH temperatures; interesting way to put it, but true if this is what he is saying. What he doesn't realize (at least, in my opinion) is that the Aqua Ch.5 temperatures and the UAH lower tropospheric are not representing the same thing. As can be seen in the link that I gave at the end of № 265, the Aqua Ch.5 temperatures are representative of middle tropospheric temperatures while the UAH are representative of lower tropospheric temperatures (The UAH are derived from Aqua data, as the link explains). Given this, it only makes sense that the Aqua Ch.5 data is cooler than the UAH LT data.

* * *

Whew! That might be my longest post ever, but I hate making several posts in a row; my experience has been that many message boards frown upon double and triple posting (or quintuple,sextuple...a la Cyclonebuster). LOL...just ribbing Cyclonebuster a bit; I don't have any problem with him...he has generally at least been respectful to me even though we typically disagree.

Yes, never mind them. I can prove to you we are causing warming without co2.

Every asphalt road we lay down decreases the albedo over that surface area of the earth creating a warmer environment.

Ever heard of the urban heat effect? Guess what, it's all part of the global atmosphere.

That's a significant impact right there, and even if we only layed one 1 mille asphalt road down, we would be having an impact on the climate and therefore be partially responsible for global warming. Just one. That's all it takes to be partially responsible.

The effects of that one road would be ridiculously small, but an impact nonetheless.

Now multiply that times a few million to get the total urban heat affect, add in the other greenhouse gasses which we are adding to, and you might see a noteworthy impact.

Quoting RMuller:

The only thing that is a hoax, if you visit the site I posted previously, is the hockey-stick graph using tree rings as data. My question is why would so-called "scientists" take the chance of deliberately manipulating data to demonstrate something that is provably false? They must be receiving some sort of large compensation for not worrying about their reputations or worse.

That's the problem, the earth hasn't been proven to be cooling.

If you don't trust the scientists, I suggest you head to the artic and see ice levels retreat for yourself, or greenland. Or even Antarctica.

If you really think scientists are lying to you, why don't you go out and do your own research instead of spitting out what some website told you.

It makes zero sense that you trust some random website on the internet over all the scientists and present data available.

Quoting martinitony:

Yes true, but let me state a skeptics view because I am a skeptic. Suppose the climate varies from its average from time to time and we decide that the average is the last 5,000 years of history because there is written history, tree rings etc.Now the question is to what extent do the controllable factors affect that change. For example if I assumed that the Earth's position relative to the sun, solar system and even itself, its axis, accounted for 95% of those variances from the norm and if I assumed that mans activities could only be controlled to affect 50% of its contribution, then controlling mans activities might only affect the variance to the extent of 2.5%. These numbers are only for example. You might argue that mans activities account for 95% of the variances from the average.

I would argue that too much of whats been going on in climate science and the "green" economy is about money. That part of the argument interferes with the truth, what the science really tells us. Both sides argue that the other is influenced by money and I'm pretty sure both sides are right about that. So, where does that leave us?

I agree the sun has a much bigger play on temps here on earth than humans do. But the solar input on our planet has not risen like temperatures have, so there is zero correlation.

And of course the green economy is about money. You can't expect this to be all non profit organizations. When it comes to business, someone will always be making the money.

The reason why a "green" economy hasn't fully taken over is that oil is still far more profitable. Hence, there is more money in fossil fuels right now.

Climategate is a hoax itself. I really don't understand why people refuse to accept the fact that our earth is warming or that we are at least partially responsible for a warm up.

Everything that makes up earth's system has an effect on temperature. EVERYTHING. we are partially responsible by the law of common sense

Yes true, but let me state a skeptics view because I am a skeptic. Suppose the climate varies from its average from time to time and we decide that the average is the last 5,000 years of history because there is written history, tree rings etc.Now the question is to what extent do the controllable factors affect that change. For example if I assumed that the Earth's position relative to the sun, solar system and even itself, its axis, accounted for 95% of those variances from the norm and if I assumed that mans activities could only be controlled to affect 50% of its contribution, then controlling mans activities might only affect the variance to the extent of 2.5%. These numbers are only for example. You might argue that mans activities account for 95% of the variances from the average.

I would argue that too much of whats been going on in climate science and the "green" economy is about money. That part of the argument interferes with the truth, what the science really tells us. Both sides argue that the other is influenced by money and I'm pretty sure both sides are right about that. So, where does that leave us?

Well, he's talking to TomTaylor, but he's referring to me, so I'm going to address a couple of things...

Blockquotes are from MichaelSTL.

"You can obviously tell that he is a [perjorative redacted], regardless of what he or others have said, because he fails to mention this (which, BTW, is 70% represented by the ocean itself, curious too that the RSS map here shows negative anomalies over the ocean where it is actually warmer at the surface):"

I can see the RSS map, but I have no idea what he wants to compare it to. If I were going to compare it a GISS map (is it even available for March yet?) I would remember to change the base period to one that coincides with the RSS map. I would also make sure to use the 250km resolution to show only areas that actually have measurements. Whatever...I'm really not sure what point he was trying to make here.

"So I guess they are subtracting the PDO from itself (according to the [perjorative redacted] anyway). Why is there a residual signal then?"

This is related to the PDO being detrended from the overall warming. "Subtracting the PDO from itself"? Again, I have no idea what he is inferring. The overall increase in global temperatures is what is subtracted out. "Why is there a residual signal then?"...Yeah, my question exactly.

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Well, that's all I have time for...If you're still there, have a good night TomTaylor.

Quoting TomTaylor:I don't know how you're reading that graph, but when I looked at it, the last 15 years are certainly warmer than the first 15. Yet the PDO graph

clearly shows that it has been dropping since the 1980s, besides a peak in the late 1990s and early 2000s (likely due to El Nino). Yet temperatures according to your graph

are not doing that.

So now, not only does correlation =/= causation, but there is no correlation in the first place.

The correlation I see between the PDO and global temperatures is as follows. When the PDO is in a primarily positive period, say a significantly positive value according to smoothed average line in the PDO graph you posted, global temperatures seem to be increasing during that time. When the PDO is in a primarily negative period, temperatures decreased. The decreases certainly do not balance out the increases, and part of the reason for this is that there is a warming signal due to CO₂ level changes that contributes as well--but there is a marked difference in the behavior of temperatures when the PDO is in a positive phase as opposed to a negative one.

Note that times when the smoothed PDO is near zero (particularly around 1945, 1975, and 2000-present) seem to correlate well with times that temperatures went from warming to cooling and vice versa. Now the last ten year period is still subject to debate because we haven't seen any decrease in temperatures to be sure, but it does seem clear that the rate of increase over the ca.1975-2000 period was much greater than the ca.2000-2010 period. You can compare respective El Niño and La Niña peaks/troughs to see this. Obviously you have to try to select similar ENSO conditions at the start/end points of any time period in order to estimate--i.e. Just as it is wrong to select a 1998-2008 and claim that there has been cooling, it's just as wrong to select a 2000-2010 period and claim significant warming.

Of course, as you say, correlation != causation, but it is at least interesting when there is a correlation. As I noted previously (and I see MichaelSTL noted in № 267) the PDO is detrended from the overall warming signal, thus there is no reason for it to correlate at all. The fact that there is a correlation is at least interesting...Well, at least to me.

Not exactly...the PDO index is detrended from the overall warming signal; the fact that there is still a correlation with the smoothed index and warming/cooling periods is at least interesting and indicative of the idea that some natural variation could be partially responsible for the warming we've seen over the last 30-40 years.

The PDO has entered an almost neutral state over the 10-15 years, and may be entering a negative state. Temperatures in the satellite record have not increased significantly over this period, as can be seen below:

The GISS graph shows this as well, to a degree. The 2000 La Ni%uFFFDa minimum wasn't really was all that much lower than the 2008 minimum, but since the 2000 was much longer in duration, it shows up lower on the GISS graph which has the 1-year average. The 5-year smoothing hides the recent trend even more.

There is a valid argument to be made that fifteen years is too short to consider the more recent trend to be indicative of a change in the longer warming trend, but it is at least interesting that it is occurring, and that it is occurring at a time when the PDO has been entering what it likely another negative period similar to that of the ca.1945-1975 period. It will be even more interesting to see what the global temperature response will be if both the PDO and AMO enter long-term (ie. ca.30 year or so) negative periods.

I don't know how you're reading that graph, but when I looked at it, the last 15 years are certainly warmer than the first 15. Yet the PDO graph

clearly shows that it has been dropping since the 1980s, besides a peak in the late 1990s and early 2000s (likely due to El Nino). Yet temperatures according to your graph

are not doing that.

So now, not only does correlation =/= causation, but there is no correlation in the first place.

Quoting MichaelSTL:"...never mind that the Aqua satellite has a cold bias..."

What...?

Nothing in the link MichaelSTL gives shows any evidence that the Aqua Satellite has a "cold bias". I'm not even sure what he is talking about. Maybe he meant to say that the UAH lower tropospheric temperatures have a cold bias compared to the raw Aqua data, at least that is the impression that I got based on the link he gave. Even that is unfounded though; I don't think MichaelSTL understands how the UAH lower tropospheric temperatures are derived. He won't see it, since I'm sure he has me on ignore, but for anyone else who would like the information I am giving Dr.Spencer's explanation below.

Did nothing to disprove that CO2 has an affect on our earth's temps. Simply tried to make CO2 seem soo small it can't do anything.

At any rate, here are the cycles:

PDO

ENSO

SOIENSOI

Neither match up to the graph:

PDO does a little, but not over the last 20 years. And, correlation =/= causation. And PDO is a measure of the SSTs over a large area in the Pacific...it's part of the temp graph itself. It would only make sense for the PDO to follow the temp graph.

[Emphasis on the last phrase is mine]

Not exactly...the PDO index is detrended from the overall warming signal; the fact that there is still a correlation with the smoothed index and warming/cooling periods is at least interesting and indicative of the idea that some natural variation could be partially responsible for the warming we've seen over the last 30-40 years.

The PDO has entered an almost neutral state over the 10-15 years, and may be entering a negative state. Temperatures in the satellite record have not increased significantly over this period, as can be seen below:

The GISS graph shows this as well, to a degree. The 2000 La Niña minimum wasn't really was all that much lower than the 2008 minimum, but since the 2000 was much longer in duration, it shows up lower on the GISS graph which has the 1-year average. The 5-year smoothing hides the recent trend even more.

There is a valid argument to be made that fifteen years is too short to consider the more recent trend to be indicative of a change in the longer warming trend, but it is at least interesting that it is occurring, and that it is occurring at a time when the PDO has been entering what it likely another negative period similar to that of the ca.1945-1975 period. It will be even more interesting to see what the global temperature response will be if both the PDO and AMO enter long-term (ie. ca.30 year or so) negative periods.

Did nothing to disprove that CO2 has an affect on our earth's temps. Simply tried to make CO2 seem soo small it can't do anything.

At any rate, here are the cycles:

PDO

ENSO

SOIENSOI

Neither match up to the graph:

PDO does a little, but not over the last 20 years. And, correlation =/= causation. And PDO is a measure of the SSTs over a large area in the Pacific...it's part of the temp graph itself. It would only make sense for the PDO to follow the temp graph.

You seem really cool. I've had the chance to review some of the previous posts of this blog and I like your intelligence and also your demeanor and disposition. At least with your writing anyway, as I don't know you in person! lol.

There is a girl or guy on here,,I think it's MichalStl or something and he/she was very mean when trying to make the point over climate change. At least I just the impression of a very cold, harsh, demeanor.

But climate change is about keeping a broad view on things. Thnx for the cool reply. :-)

Regards,Ainslee.

No problem, bud

And keep in mind that although that's what most meteorologists, like Dr. Masters, predict, it doesn't mean it will come true.

It's no different than the weather guy on TV; he's usually correct for the most part give or take a few degrees, but occasionally he misses something.

Quoting cat5hurricane:Yeah Taylor's a good guy. We'll occasionally have a beer together in Master's blog. We usual don't see eye to eye with respect to climate change, but he always makes the attempt to lay it out for you and doesn't attack.

There's been a lot of talk about this, especially since the findings are still in the very early stages.

The official findings are here. As is explained in the official findings, even the 2% of data that has been compiled has yet to be corrected for urban heat effects, varying time of observation etc. Bottom line is that it's still too early too make any definitive conclusions. BEST very well may end up vindicating existing temperature reconstructions but to say that it has already done so is premature and misleading. There seems to be a significant effort by some to shape the results before they are official. I would wait until the analysis is done and draw conclusions then. Even if doesn't end up being significantly different than other reconstructions, I thinks it's good to have the BEST record as an alternate going forward simply due to the level of openness that is expected as well as the more balanced makeup of the people involved.

That is Atlantic ACE only, not global, and 2010 isn't shown since the graph was made before then. Atlantic has been generally high during the ca.1995-2010 period but it's no secret as to why this is--it's due to the AMO.

№ 250

Quoting cyclonebuster:

At what ACE do we get Hypercanes?

OK. I had to look up "hypercane"...From Wikipedia:

"A hypercane is a hypothetical class of extreme tropical cyclone that could form if ocean temperatures reached around 50 °C (122 °F), which is 15 °C (27.0 °F) warmer than the warmest ocean temperature ever recorded."

This will simply not happen from an increase in greenhouse gases alone. Some extreme event well beyond our control such as a asteroid impact would be required, so I wouldn't worry about it.

Methane gas comes from all sorts of sources including wetlands, rice paddies, cow tummies, coal mines, garbage dumps and even termites. Drew Shindell, at NASA's Goddard Institute in New York, says, "It's gone up by 150 percent since the pre-industrial period. So that's an enormous increase. CO2, by contrast, has gone up by something like 30 percent."Link

I wonder if the plant eaters moved humans out of thelast ice age? Not likely.

Quoting InconceivableF6:Is that what they are using now claim AGW? Lower storms, but more intense, right. I remember back just a couple years ago in the wake of the 2004 and 2005 season that it was more storms.

Predicting the future effects and implications of a warmer climate is very hard.

With that said, as far as tropical cyclone formation goes, latest evidence points out that in a warmer global climate the poles will experience greater warming than the tropics. The entire purpose of a tropical cyclone is to attempt to work out some of the temperature imbalance between the tropics and the poles by transporting some of the heat of the tropics toward the poles. When the difference in temperatures decreases between the poles and the tropics, as it would under a warmer climate, the need for tropical cyclones declines.

Therefore, it is predicted that under a warmer climate there would be fewer storms. Additionally, however, under a warmer climate, the oceans will be warmer providing more "fuel" for hurricanes. Which is why they predict stronger storms in the future. Of course that's just a prediction. It's not a statement of truth. So if it doesn't come true, don't be surprised.

Like sirmaelstrom said, the idea the thought that we would experience more storms was probably more propaganda than anything. It is scientifically supported since warmer SSTs are more conducive for tc formation. But SSTs are not the only factor involved in tc genesis.

So the prevailing idea is that in the long term future is more intense storms but fewer total storms. Once again, keep in mind this is only a prediction. Should it come true, or false, has nothing to do with the validity of the earth warming or humans contributing to the warming.